Base for electric lamps and the like



June 26, 1945. C: A BRQWN ETAL 2,379,063

BAs FOR ELECTRICLAMPS AND THE LIKE Filed Oct. 16, 1944 [NVM/TM5. -CARLALBA/UWM CLARE/V55 5 HAH/V THE/R A7 TURA/fy- Patented June 26, 1945 BASEFOR ELECTRIC LADIPS AND THE LIKE Carl A. Brown, Chardon, and Clarence E.Hahn,

Euclid, Ohio, assignors to General Electric Company, a corporation ofNew York Application October 16, 1944, Serial No. 558,888

3 Claims.

This invention relates to basing electrical devices, including bases forthe bulbs or envelopes of incandescent lamps as well as discharge lampsand other discharge devices of various kinds. It is concerned with thestructure of the base and with conditions that may arise from itsattachment to an envelope end or neck. The invention is hereinafterexplained with particular reference to bases of the Edison and kindredscrew and center contact types, though it is also applicable to bases ofvery different types from this, such as the double end-contact bayonettype, for instance.

Bases are very commonly secured to envelope ends or necks by means ofbasing cement which.

requires time and heat to harden, set, or cure it. It is desirable tocomplete all other operations on the electrical devices before basingthem, which includes the -connection of the base contacts to the currentleads of the devices. The bases and their end contacts are apertured forthe passage of the current leads; but these leads are electricallyconnected to the end contacts by methods which usually result in closingthe openings, such as soldering. This may leave the interior of a basecompletely closed off, with no possible escape for gases evolving fromthe basing cement during the hardening or curing, or even after thedevices have become hot in service. Owing to the heat, the pressure ofthe confined gases may become high enough to rupture or crack the bulbend inside the base, or the stem tube that opens through the bulb endinto the interior of the base,

. or the exhaust tube inside this stem tube; or it may in some casesexpand the screw shell of the base so that it no longer turns freely inthe corresponding lamp socket, or may blow the base oi the bulb.

An object of this invention is to obviate such trouble from confinedgases in a base by providing a vent to the outside that will not beclosed in the usual operations of basing the lamp and connecting itsleads to the base contact(s). As particularly described hereinafter,this is accomplished very simply and conveniently, without complicatingthe base structure, without requiring any extra operation in basemanufacture, and without increasing the cost of the base in any way.Other features and advantages of the invention will become apparent fromthe descrip` tion of species and forms of embodiment, and from thedrawing.

In the drawing,

Fig. 1 shows an axial section through a lamp bulb neck and a baseembodying the invention, a portion of the lamp bulb appearing inelevation;

Fig. 2 is a side or edge view of one part of the base; and Figs. 3 and 4are top and bottom views of the same part.

Fig. 5 is a fragmentary section similar to part of Fig. l, illustratinga modification.

Figs. l to 4 illustrate the application of our invention to an Edisonscrew base I of the general type illustrated in U. S. patents, Nos.2,184,269 and 2,210,525 to Brown and Hahn, comprising a sheet metalscrew shell 2 having at-its outer end a seat Ii, and a button-likebase-end insulator 4 laterally abutting the seat 3 and secured thereto.As shown, the inner end of the base shell 2 is cir- Acumposed about thereduced end or neck 5 of a per edge 9 of the seat 3 on the edge of thebutton.

To hold the insulator 4 against rotation on its seat 3, its upper outeredge I0 may have rounded top projections or teeth against which thesheet metal at 9 is depressed and interlocked. The seat 3 is shown asreinforced and stiffened by turning the inner margin of the fiange 8downward from its general plane, as a supplemental flange or lip II.Another feature not shown in the aforesaid patents is a centrallyapertured sheet metal end contact disc I2 having a hollow shank embeddedin the glass or other insulative material of the button 4, which iscentrally apertured in correspondence with the disc and shank openings.

A leadwire I3 from inside the bulb B is shown threaded through thecenter hole in the insulation 4 and the disc I2, and may be soldered tothe latter at I4, where it is cut off. In the case of a device with twoleads to its filament or electric translation means, the other lead I5may be retroverted to extend down between the bulb neck 5 and the screwshell 2 to its lower edge, and there brought out and soldered to theshell at I6. These center contact and leadwire features are similar tothose of Edison screw bases in general use prior to the aforesaidpatents.

For the purposes of our invention, we provide one or more openings orchannels at or in the interengaging surfaces of the parts 2 and 4, bylocal deformation thereof. As shown in the drawing, the openings areprovided at the exequally spaced around it. The depth of the notches I'Iat their top openings exceeds the overhang of the inturned seat edge 9,and the bottom openings of the notches or of the grooves I8 extendinside the zone of Contact of the button 4 breathing openings formed inthe seating portion III of the base end insulator 4, and open past theshell seat, for the escape of gas from inside the base I, or for theentrance of the outside air. The external mouths of these openings aresheltered behind the shell seat overhang 9, Where they are almostimperceptible and indistinguishable from with the seat iiange 8. Thusthere are vent and the spaces between the teeth on the insulator edge YI0, and little liable to be clogged wtih dirt. The mouths of theseopenings inside the shell 2 are at the top of the latter and shelteredby the flange lip II, so that they are not likely to be clogged by dirtbefore the base is applied to a lamp, nor by the basing cement at alower level in the shell, around the bulb neck 5.

In manufacture, thev insulator 4 may be formed by die-pressing ormolding any suitable glass, such as that used for the insulator buttonsin the aforesaid patents, or for the insulative parts of the Edisonscrew bases in common use prior to said patents. The contact discs I2(with their Shanks) may be placed in the molding dies before the glassis introduced and thus molded into the insulators. The vent openingrecesses (notches lI'l with or without grooves I8) may be formed in theinsulator margins as an incident of the molding operations, by Suitableprojections on the corresponding surfaces of the dies. Thus the ventopenings are provided without any special operation or extra cost.

In Fig. 5, various parts and features are marked with the same referencenumerals as those corresponding in Figs. 1 to 4, in order to dispensewith repetitive description.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. In an electrical device comprising a bulb having a neck portion witha lead wire extending therefrom; a metal base shell circumposed aboutand internally cemented to the bulb neck, and having an end seat at itsouter end; and a base-end insulator button abutting and secured to saidseat carrying an end contact electrically connected to said lead wire,and provided with a vent in its own seating portion open past the shellseat.

2. In a base construction for electrical devices of the characterdescribed, the combination of a metal 'shell having an end seat; and abase-end insulator button abutting and secured to said seat, and havinga vent opening past the shell seat formed in it at the expense of thematerial of its seating portion.

3. In a base construction for electrical devices of the characterdescribed, the combination of a metal shell having its outer end doubledinward and flanged, and overhanging the rabetted seat thus formed; and abase-end insulator button `seated in said seat and peripherally held inby the overhang aforesaid, but notched across its periphery to a depthgreater than said overhang and grooved across itsseating surface in com.

munication with its peripheral notching.

CARL A. BROWN. CLARENCE E. HAHN.

